Radio Frequency (RF) shielding may be required on certain semiconductor devices and modules (hereinafter semiconductor device) in order to minimize Electro-Magnetic Interference (EMI) radiation from the semiconductor device. RF shielding is further required to prevent RF radiation from external sources from interfering with operation of the semiconductor device. In a semiconductor device which integrates multiple functions/modules (front end module+transmitter, radio+baseband, etc.) compartmental shielding may be required to minimize EMI radiation from the different components/modules and to prevent RF radiation from interfering with operation of the different components/modules in the semiconductor device.
There are several different methods used for compartmental shielding of semiconductor devices which integrates multiple functions/modules. Known methods of compartmental shielding include embedded shields, metal cans with compartmental features, wire fences, and laser ablated vias. Presently, there are issues with shield effectiveness in mold cavities. Existing solutions such as wire fence and via ablation have reduced performance as the mold cap gets thicker because the gap between ground structures increases. Even multi-tier wire fence cannot resolve this issue completely. Thus, it is beneficial to reduce the maximum gap between ground structures in order to increase shield effectiveness.
Furthermore, in Through Mold Via Package on Package (TMV PoP) shielding, a two tier mold cap may be used. In this type of packaging, a wire fence may be required to shield the perimeter of the module because it may be difficult to perform laser ablation of the TMV vias after singulating the units as is required for a full saw shield structure. Wire fence may be difficult to implement on a two tier structure. Thus, it would be beneficial to have a consistent wire loop height around the module where one could saw in order to cut through the thick portion of the mold cap to expose the wires.
Therefore, a need existed to provide a system and method to overcome the above problems. The system and method would provide for a more effective RF shield for a semiconductor device.